The present invention relates to valves and, more particularly, to solenoid valves for use in micro-gravity environments, for use in vibration environments, and for use with high pressure fluids.
Solenoid valves are typically made by manufacturing a solenoid subassembly separately from a valve body subassembly and then coupling these subassemblies together. Certain solenoid valves provide for the subsequent uncoupling of these two subassemblies, for instance, to replace the solenoid. Threaded fasteners or snap rings have been used to couple solenoid subassemblies to valve body subassemblies. For example, Skinner's solenoid valves typically use a threaded nut, paired with a washer, to couple the solenoid subassembly to the valve body subassembly. During the replacement of a solenoid subassembly, these threaded fasteners, washers, or snap rings are separated from the subassemblies and become small, loose items. Such small, loose items are easily lost or misplaced. In a microgravity environment, such small, loose items can float away and create dangerous situations. For instance, a loose nut could become lodged between an airlock door and its frame, preventing its airtight closure.
The typical solenoid valve includes a slidable plunger that moves from a first non-actuated resting position when the solenoid is not energized to an actuated position when the solenoid is energized. This plunger may be directly coupled to the valve element that seats against the valve seat when the valve is closed. In such instances, the plunger may be spring biased in order to bias the valve element in either an open or closed position. Alternatively, the plunger may interact with a poppet, rather than be directly coupled to the valve element. In such plunger/poppet valves, the poppet, not the plunger, is spring biased in either an open or closed position. Given sufficiently high vibration loads, the plunger of such a poppet/plunger valve may be moved from its non-actuated resting position to its actuated position even if the electromagnetic coil is not energized. Under these conditions, the vibration loads could cause the unwanted opening (or closing) of the valve.
When a valve is closed, it is desirably to not have any leakage past the valve seat. Providing an adequate seal between the valve element and the valve seat can become a significant problem if the fluid controlled by the valve is under high pressure.
The valve of the present invention is intended to solve one or more of the problems set forth above.